Fibroblast growth factor-23 (FGF23 or FGF-23) is a hormone that regulates phosphate level through an action on the reabsorption of phosphate from the kidneys. FGF23 was cloned initially from mice using PCR methods based on sequences derived from database searches using sequence homology with FGF15. Human FGF23 was cloned by using sequence homology with mouse FGF23 (Yamashita, T. et al., Biochem. Biophy. Res. Commun., 277: 494-498, 2000).
Recent studies have shed new light on the understanding of phosphate metabolism. Phosphate has important functions in the body and several mechanisms have evolved to regulate phosphate balance including vitamin D, parathyroid hormone and phosphatonins such as FGF23. Disorders of phosphate homeostasis leading to hypo- and hyperphosphataemia are common and have clinical and biochemical consequences.
Despite the previous findings, there remains a need for more effective methods for treating disorders related to abnormal phosphate metabolism, such as disorders related to abnormal FGF23 signaling, and methods for evaluating the efficacy of the treatment. The present invention meets this need and provides compositions and methods for the effective treatment of such disorders.